Beamrider missile systems utilize a form of line of sight missile guidance in which a beam of spatially encoded electromagnetic radiation is projected in the direction of a target and a rearward-looking missile-borne receiver decodes the spatial information and thereby determines the missile's position within the beam. The missile corrects its position as necessary to remain at or near the beam center until target impact.
Among previously known forms of beamrider spatial encoding, some are not suitable for use at longer wavelengths where atmospheric transmission is better, where use of a single radiation source is more desirable for cost and size reasons, and where diffraction limits the beam resolution attainable. Of those which are suitable for use at longer wavelengths, all have one or more other disadvantages such as requiring a more technically difficult pulsed source, requiring more complex decoding electronics on the missile, and requiring complex optical and/or mechanical parts in the projector, requiring maintenance at a prelaunch synchronized clock phase on the missile during flight, and failing to provide any means of encoding rate bias for moving targets. Therefore, it can be seen that there is a need for a beamrider missile system that can overcome disadvantages of other devices.
In view of the need, it is an object of this invention to provide a tone burst reticle beamrider missile guidance system that overcomes disadvantages of prior devices.
Another object of this invention is to provide a tone burst reticle beamrider missile system which utilizes a reticle with optically transparent and opaque surfaces thereon and so arranged to allow two tone bursts to be projected toward a missile receiver for guidance of the missile.
Still another object of this invention is to provide a tone burst reticle beamrider missile system in which the reticle thereof produces tone bursts that are asymmetrically spaced in time.
Other objects and advantages of this invention will be obvious to those skilled in this art.